Ventilated light-responsive lampchanging mechanism for lighting units



March 25, 1952 R. E. CROSSLEY ET AL 2,590,513

VENTILATED, LIGHT-RESPONSIVE, LAMP-CHANGING MECHANISM FOR LIGHTING UNITSFiled Feb. 19. 1947 3 Sheets-Sheet l Harl w/V. Pdi'bdfi b 203/42 2 53???BMW. ew

March 1952 R. E. CROSSLEY ET AL 2,590,513 VENTILATED, LIGHT-RESPONSIVE,LAMPTCHANGING MECHANISM FOR LIGHTING UNITS Filed Feb. 19, 1947 3Sheets-Sheet 2 M/l l ....JJ ELL.

l and Roya) 6. Crude 1 M, f1 E El 43 4 HdHow/ZPafiat INVENTORS.

March 25, 1952 R. E. CROSSLEY ET AL 2,590,513

VENTILATED, LIGHT-RESPONSIVE, LAMP-CHANGING MECHANISM FOR LIGHTING UNITSFiled Feb. 19, 1947 3 Sheets-Sheet 3 78HdrZow/1fl1wai: INVENTORS- andRoy-a) 6. Cross/e BY 76 Aw Patented Mar. 25, 1952? VENTILATED.LIGHT-RESPONSIVE LAMP- CHANGING MECHANISM FOR LIGHTING UNITS Royal E.Crossley, Fayetteville, and Harlow M. Pattat, North Syracuse, N. Y.,assignors to Grouse-Hinds Company, Syracuse, N. Y., a corporation of NewYork Application February 19, 1947, Serial No. 729,556

' 6 Claims.

This invention relates to mechanism for automatically changing lamps inan electrical lighting unit.

The invention has as an object, a mechanism of the type referred toprovided with a plurality, or series, of lamps, and being operableautomatically to successively move the lamps into the focal axis of thelighting unit when the light output of the lamp in the focal axisreaches a predetermined minimum, thus assuring an emcient operation ofthe unit at all times.

The invention has as a further object, lamp changing mechanismincorporating a structure by which high intensity lamps may be used,that is, lamps of small dimension with exceptionally high wattage, suchas small high wattage mercury vapor lamps, the mechanism embodying astructure operable to efiectively cool such lamps while they-are beingburned in operative position.

The invention has as a further object, a lamp changing mechanismembodying a structure operable to move a new lamp into operativeposition after the light output of the preceding lamp has reached apredetermined minimum for a'period of time, and which is operable toeffect the substitution of a successive lamp only after the lamppositioned-in the focal axis of the unit has been so positioned forapredetermined length of time. This arrangement is eiiective to prevent alamp being moved out of operative position 'and a new lamp substitutedin the event of a momentary drop in the light output of the lamp causedby a voltage drop in the line, or a temporary power interruption. Italso prevents the rapid substitution of -a seriesof lamps, the flashingof which might be confused with a code signal customarily used oncertain airway beacons.

The invention consists in the novel features and in'the combinations andconstructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanyingdrawings in which like characters designate corresponding parts inallthe views.

Figure 1 is a side elevational view of a lamp changing mechanismembodying -my invention with contiguous parts of the lighting unit shownin section.

Figure 2 is a front elevational view, looking to the right, Figure 1, ofthe lamp carrier and contiguous parts of the associated mechanism.

Figure 3 is an enlarged side elevational view of the structure "shown.in Figure .2.

Figure 4 is an enlarged front elevational view, looking to the right,Figure 1, of the mechanism for eiTecting movement of the lamp carrier.

Figure 5 is a side elevational view of the structure shown in Figure 4.

Figure 6 is an across the line schematic Wiring diagram of the circuitemployed in connection with the mechanism shown in Figures 1 to 5inclusive.

In Figure l, the lamp changing mechanism is shown mounted in a lightingunit ofthe searchlight or beacon type, comprising a cylindrical casingl8 having a transparent lens H and a reflector 12. The lamp changingmechanism comprises a lamp carrier [3 movably mounted upon a support I4secured to a bracket comprising a casting 15 supported on a stem itwhich, in turn, is carried by an arm I! secured to the casing In of thelighting unit. The'stem I6 is connected to the arm H by any suitablemeans, as l8, whereby the support is may be adjusted universally toaccurately position one of the lamps, as 20, in the focal axis of theunit.

As here shown, the mechanism is intended particularly for using mercuryvapor lamps which are of relatively small dimension, but which have anoutput in the neighborhood of 900 watts. These lamps consist of a smalltransparent tube 2| provided with a metallic ferrule .22 on each end,and the carrier I3 is provided with a plurality of pairs of clipterminals 23. The carrier is of general U formation, being formed withside plates 24, 25, secured to a back plate 23, as by screws 2?. Theback plate 2.6 .is formed with a pair of spaced apart in wardlyextending lugs 28 apertured to receive a pivot pin 29 also extendingthrough a pair of lugs 30 extending from ahead piece 3] carried on theend of the support i i, whereby the carrier is movable about the pivot29. The clips 23 are mounted on the side plates 24, 25, on a radiusstruck from the axis of the pivot, all whereby the lampsZU, 3!, 22 and.33 move in an are about the pivot and, as previously stated, thelampf20 is illustrated as being positioned .in the focal axis of theunit. When-the light output from this lamp reaches a predeterminedminimum, the carrier is moved about the pivot 29, bringingthenext'succeedinglamp 31 of the series into operative position. Thatis, intermittent movement of the carrier l3 about the pivot 29successively positions the lamps of the series in the focal axis of thereflector l2. The carrier may be constructed to take any :number oflamps. However, in ordinary use, four have been found to be entirelysumcient.

The spring clips 23 are formed with straps 34 overlying the outer sidesof the plates 24, 25, and being secured thereto, as by screws 35. Theplate is formed of metal. The plate 24 however, is formed of insulatingmaterial and provision is made to provide current to energize the lampin operative position. The head piece 3! is formed with a centrallyarranged arm 38 to which is secured a bracket 39, as by screws 40, andwhich extends laterally beyond the plate 24, and to the outer end ofwhich is secured a strip 42 of insulating material, as by screws 43. Astrip of conducting material it is secured to the opposite end of theinsulating strip 42, as by screws 45, one or both of which may serve asterminals to which one of the power wires is secured. The upper end ofthe strip 44 is provided with a brush 46 extending inwardly between thescrews and contacting the straps 34, the brush 46 being so positioned asto contact the strap of the terminal, or clip, of the lamp in operativeposition.

The lamp carrier is connected to a link at extending rearwardly andbeing pivotally connected to one end of a cross member 39, the oppositeend of which is secured to a quadrant 50 mounted upon a pivot pin 5!carried by a pair of upstanding bosses 52 forming part of the castingl5, which is also formed with a trough shaped portion 53 extending inangular relation to the stem i5 and in which the support 14 is secured,as by being welded thereto.

The quadrant 53 is urged in a counter-clockwise direction, Figure 5, bya torsion spring 5 5 and tends to likewise urge the lamp carrier 13 in acounter-clockwise direction, Figures 1 and 3. The lower arcuate surfaceof the quadrant is formed with teeth-like projections 55 which areengaged by a restraining member 55 pivotally mounted at 51. There is oneof the projecting teeth 55 for each lamp in the series carried by thelamp carrier. It will be understood that the arrangement of the teeth 55is complemental to the arrangement of the lamps carried by the carrier[3.

Usually lamp changing mechanisms are operable after the lamp in operatedposition has burned out. This is brought about by mechanism operableupon current failure resulting from the burned out filament in the lamp.It is desirable, in many instances, that the lighting unit maintain adesired efficiency, or light output, and we have incorporated in ourmechanism means whereby the replacement of a lamp, when it reaches thepredetermined minimum efficiency, is moved out of operative position,and a new lamp substituted for it. For example, the mechanism mayoperate to shift a new lamp in operative position when the light outputof the previous lamp has dropped to forty or fifty percent. There isarranged in the casing, and under the influence of the light output ofthe operative lamp, a light actuated switch 55, the contacts of whichremain closed while the light output of the operative lamp is above apredetermined minimum. However, when the light output of the lampreaches the predetermined minimum, the contacts of the switch 50 open,and the opening of this switch effects operation of mechanism to movethe restraining member 56 out of engagement with the projection 55 withwhich it is in engagement at the time, and thus permitting the spring 54to eifect movement of the lamp carrier about its pivot 29 to bring thenext succeeding lamp of the series into operative position. The lightactuated switch referred to may be of the type sold by the MercoidCorporation, Chicago, Illinois, under the trade name Visafiame. Switchesof this type are referred to in Patents No. 2,159,392 and No. 2,171,861,issued to I. E. McCabe, May 23, 1939 and September 5, 1939,respectively. These switch units are adjustable to operate at variouslight intensities and accordingly the lamp shifting mechanism can be setto operate at any desired eificiency of light output.

Referring to Figure 6, power is supplied from the conductor 62 to amovable contact 53 of a latch relay, the contact 53 of which is inengagement with contact 64 connected to the heater 55 of a time delayrelay by conductor 55. The opposite side of the heater 65 is connectedto the common return leg 61 of the circuit through conductor 58. Theheater 65 is constructed, or adjusted, to require approximately oneminute to close its contacts 69, 15. The conductor 65 also furnishescurrent to the operating coil H of the latch relay, the opposite end ofthe coil being connected to contact 69 through conductor 12. Thus, whenthe contacts 69, 10, close, the circuit to the common conductor 5'. iscompleted by conductors 13, 68.

When the coil H is energized, the movable contact 53 is moved upwardlyinto engagement with the contact 15 and is held in this position by alatch 75. Contact 75 is connected to a solenoid 'E'i mounted on thebracket I5 and having a plunger 18 adapted, when the coil Tl isenergized, to engage the restraining member 56 and move itcounter-clockwise about the pivot 51, thereby releasing it fromengagement with the teeth 55 of the quadrant 55. This connection iseffected through a conductor 89, the opposite side of the solenoid coilll being connected to a contact 82. Power is also furnished from contact15 to a coil 83 which, when energized, moves the latch 15 out oflatching engagement with the contact 53, permitting it to drop intoengagement with contact 5 The opposite side of the coil 83 is alsoconnected to the contact 82 through wire 84. The conductor alsofurnishes a feed to the heater 85 of a time delay relay 87, the oppositeside of the heater being connected to the common side of the line 5'!through a conductor 88 and if high voltage is used on the circuit, aresistor 89 may be employed. The movable contact 56 of this time delayrelay is normally out of engagement with the contact 52 and accordingly,there is no return provided for the solenoid l? and latch coil 83. Theconductor 80, from contact 15, is also connected to the switch 65, theother side of the switch being connected to line 61, or to the resistor89, if used.

With this arrangement, it will be observed that the switch 56 isconnected in shunt with the heater coil 86 and thereby short-circuitsthe same while the contacts of the switch 69 are closed, and thatsituation prevails, as previously stated, while the output of theoperative lamp is above the predetermined minimum. When the light outputof the operative lamp falls to the predetermined minimum, the contactsof the switch 60 open and current accordingly flows through the heatercoil 88, causing the contacts 82, 55, to close. When this takes place,the circuit through the solenoid 11 is completed, effecting release ofthe restraining member 56 resulting in the movement of the carrier 13 tobring the next succeeding lamp in the series act-co ns ,einto operativeposition'and simultaneously, the

circuit .is completed through the latch coil 83, causing contact 63 tomove out of engagement with contact 15 and into engagement with contact64. The time delay relay 8'! is likewise ad justedfor approximately oneminute operation. In other words, the light output of the effective lamphas to drop to the predetermined minimum and remainthere for the periodrequired for the relay 81 to close its contacts 82, 96. This preventsthe substitution of a new lamp in case of a momentary voltage drop, orpower interruption. Likewise, the time delay relay 65 is effective toprevent a suceeding substitution to take place immediately in view ofthe fact that the control circuit for the solenoid 1'! does not becomeenergized until the contacts 69, it, of relay 65 close. This arrangementprevents the possibility of the new lamp flashing on and failingimmediately followed by the substitution of the next lamp within a shortspace of time. Such a situation might indicate an erroneous code signalto an airplane pilot and lead to a disastrous result.

As illustrated in the drawings, the support 14 consists of a tubularmember, and the head 3| connected thereto is provided with dischargenozzles 200 arranged in proximity to the lamp positioned in the focalaxis of the unit. The nozzles directing streams of a gaseous coolingmedium, such as compressed air, on the lamp to maintain the same atoperating temperature. The rear end of the member it is connected to apipe 20! supplied with a gas under pressure as by a conventional aircompressor.

What we claim is:

1. A lamp changing mechanism for lighting units comprising a tubularsupport arranged in the unit and being connected at one end to a supplyof cooling medium and terminating at its inner end in juxtaposition tothe focal axis of the unit, a lamp carrier movably mounted on the innerend of said support and being adapted to carry a series of at leastthree lamps and being movable to successively position the lamps of saidseries in the focal axis of the unit, a nozzle secured to the inner endof said tubular support and arranged to discharge the cooling medium onthe lamp positioned in said focal axis, and means operable when thelight output of the lamp positioned in said focal axis drops to apredetermined intermediate percentage to effect movement of said carrierto position the next succeeding lamp in said focal axis.

2. A lamp changing mechanism for lighting units comprising a supportarranged in the unit, a lamp carrier mounted on the support and beingadapted to carry a series of at least three lamps and being movable onthe support to successive positions for successively positioning thelamps of said series in the focal axis of the unit, means urging saidcarrier to said successive positions, a restraining member operable tohold said carrier against such movement, an electro-responsive deviceoperable when energized to release said restraining member, a powercircuit, a relay, said electro-responsive device being connected in thepower circuit through normally open contacts of said relay, a branchcircuit including the coil of said relay, a light actuated switchconnected in shunt with said coil and being arranged under the influenceof the light output of the lamp in the focal axis of the unit, saidswitch being operable to maintain its contacts closed and thereby shortcircuit said coil while the light output of said lamp is above apredetermined minimum, and to cause said contacts to open when saidlight output reaches said predetermined minimum, and means operable toenergize said circuits a predetermined time after said lamp has beenpositioned in the focal axis of the unit.

3. A lamp changing mechanism for lighting units comprising a supportarranged in the unit, a lamp-carrier mounted on the support, a series ofat least three lamps mounted on said carrier and said carrier beingmovable on the support to successively position said lamps in the focal.axis of the unit, carrier restraining means operable to hold saidcarrier in any selected one of such successive positions, a releasingmember operable when energized to release said restraining means, andmeans operable to effect movement of said carrier upon such release tothe next successive position, a light actuated switch mounted in theunit under the influence of the light output of the lamp positioned insaid focal axis and being cooperable when the light output of said lampdrops to a predetermined minimum percentage to effect energization ofsaid restraining means, and time delay means operable to render saidlight actuated switch ineffcctive until the elapse of a predeterminedtime after the positioning of each lamp.

4.. 5 lamp changing mechanism for li hting units con'iprising a supportarranged in the unit, mp carrier mounted on the support, said lpl beingadapted to carry a series of at least three lamps and being movable onthe support to successively position said lamps in the focal axis of theunit, electro-responsive means operable when energized to effectmovement of said carrier to position the next suceeding lamp in saidseries in the focal axis of the unit, a light actuated switch mounted inthe unit under the influence of the light output of the lamp positionedin said focal axis and being cooperable when the light output oi; saidlamp drops to a predetermined minimum percentage short of completeextinguishment to effect energization of said electro-responsive means,and time delay mean operable to prevent such energization until theelapse of a predetermined time after the light output of said lamp dropsto said predetermined minimum percentage.

A lamp changing mechanism for lighting units comprising a nozzle fixedlymounted in the unit in juxtaposition to the focal axis thereof, acarrier movably mounted in the unit and being adapted to carry a seriesof at least three lamps and being movable successively to position saidlamps of said series in the focal axis of the unit and in registrationwith said nozzle, said nozzle being operable to discharge a coolingmedium on the lamp positioned in said focal axis, electroresponsivemeans operable when energized to efeat movement of said lamp carrierthrough said successive positions, a light actuated switch mounted inthe unit under the influence of the light output of the lamp positionedin said focal axis and being cooper-able when the light output of saidlamp drops to a predetermined minimum percentage short of completeextinguishment to effect energization of said electro-responsive means.

A lamp changing mechanism for lighting units comprising a supportextending transversely of the focal axis of the unit, a nozzle securedto the inner end of said support in juxtaposition to the focal axis ofthe unit and arranged to discharge a cooling gas on a lamp positioned insaid focal axis, a lamp carrier movably mounted on the inner end of saidsupport and being adapted to carry a series of at least three lamps andbeing movable to successively position the lamps of said series in thefocal axis of the unit, electro-responsive means operable when energizedto effect movement of said carrier to position the next succeeding lampin said focal axis, a light actuated switch mounted in the unit andarranged under the influence of the light output of the lamp positionedin said focal axis and being cooperable when the light output of saidlamp drops to a predetermined minimumv percentage short of completeextinguishment to eff ect energization of said electro-responsive means.

ROYAL E. CROSSLEY. HARLOW M. PATTAT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

